Monocyte chemoattractant protein-1 in the aqueous humour of patients with age-related macular degeneration

Background: To investigate the role of inflammation in age-related macular degeneration by measuring the levels of cytokines in the aqueous humour. Methods: Samples of aqueous humour were collected from 34 patients with age-related macular degeneration and 16 age-matched control subjects undergoing cataract surgery. Age-related macular degeneration stage was determined clinically, before surgery. Levels of cytokines were measured using Luminex X-MAP technology, and positive results were verified by Western blot. Results: Age-related macular degeneration was moderate in 18 patients and advanced in 16. The advanced age-related macular degeneration group was further divided into patients with active choroidal neovascularization (n=7), disciform scar (n=7) or central geographic atrophy (n=2). Higher-than-normal levels of monocyte chemoattractant protein-1 in the aqueous humour were associated with advanced age-related macular degeneration (200±140pg/mL vs. 100±61pg/mL; P=0.03), especially active choroidal neovascularization (255±155pg/mL; P=0.02), Western blot analysis verified the monocyte chemoattractant protein-1 findings. Patients with disciform scar showed a trend of abnormally high levels of interleukin-12 (p70) (1.7±2.4pg/mL vs. 0.2±1pg/mL; P=0.07), tumour necrosis factor-α (1.8±2.4pg/mL vs. 0.3±1pg/mL; P=0.06) and interleukin-12 (4.7±6.4pg/mL vs. 1.2±2.1pg/mL; P=0.08). Conclusion: Elevated levels of inflammation-related cytokines in the aqueous humour in various stages of age-related macular degeneration may suggest a pathogenic role of inflammation. Monocyte chemoattractant protein-1 may be indicative of the angiogenic phase. Further corroborative studies are required.